Nintinol self-expandable metallic stenting in management of malignant obstructive jaundice: a case series.

BACKGROUND AND AIMS
Palliation therapy is the only available therapeutic method for most patients with tumor-induced obstructive jaundice. Metallic stents are now performed percutaneously as an alternative route to the endoscopic approach. It is widely accepted because of its safety, good patency rate, and minimal invasiveness. This study was designed to evaluate the long-term results of metallic self-expandable stent insertion in patients with malignant stenosis of the biliary tree.


METHODS
It is a longitudinal study of patients with percutaneously biliary stenting from September 2005 to March 2009. The patients had unresectable malignant biliary obstruction with unsuccessful endoscopic stenting and access. Percutaneous transhepatic cholangiogram performed after adequate local anesthesia, under sonographic or fluoroscopic guidance. Stenting or balloon dilation was performed through the hydrophilic guide wire. Among 50 patients, 45 stents were placed in biliary tree stenosis sites. Patients' follow-up was during the first, second, third, and then the sixth month after insertion of biliary stents. Stent patency was considered successful in our patients, when there were no lab results or sonographic appearance of biliary tree obstruction.


RESULTS
10(20%) patients' stent placement treatment failed because of unsuccessful technical procedure. The stenosis of biliary tract was complete and passage of guide wire was not possible through the tumor growth. 6 (15 %) patients with successful stent placements died within one month (mean, 22 days). Total serum bilirubin resolved to below 1.5 mg/dl within 30 days for 36 (90%) patients with successful stent placements. Early complications not leading to death occurred in 28% of cases. The mean survival time for all patients who underwent stent placement was 140 days (16-420days). The mean patency rate for all stents was 147 days.


CONCLUSIONS
Percutaneous biliary stenting is a safe procedure with few technical complications and a high success rate of palliation for patients with malignant biliary jaundice. Early complications are mostly managed conservatively and death is mainly due to systemic effects of the malignant disease.


Introduction
M alignant obstructive jaundice is a poor prognostic disease with important consequences for the patient's lifestyle and survival. Most of the patients will die during the first six months after diagnosis.
There is no curative therapy for the disease, but stenting and drainage of the biliary tree have been proven as a safe method with few technical complications. Percutaneous transhepatic insertion of metallic stents is now a reliable method for Percutaneous Biliary Stenting palliation of patients with obstructive malignant jaundice, which is superior to plastic endoprosthesis when we consider the aspects of patency rate, quality of life, complication rate, and the cost of procedure (1,2) .
In this study we decided to evaluate the long-term results of metallic self-expandable stent insertion in patients with malignant obstructive stenosis of the biliary tree. We observed the complications, the technical and clinical successfulness of the procedure, and the follow-up of patients referred to Imaging Medical Center as a tertiary center for palliation therapy.

Material and Methods
This is a longitudinal study of 50 patients with unresectable malignant biliary jaundice who were referred to our center for palliation therapy using nitinol self-expandable metallic stents.
All patients were evaluated at the Imaging Medical Center (Imam Khomeini Hospital), and selected from a database of patients between September 2005 and March 2009.
The patients attending our center had unresectable malignant biliary obstruction; therefore, endoscopic retrograde cholangiopancreatography (ERCP) was not successful or possible and endoscopic stenting was not performed because of lack of endoscopic access.
Among 50 patients, two radiologists placed 45 stents into the biliary tree stenosis sites. This was done using the percutaneous route and transhepatic cholangiogram. The procedure was performed after adequate local anesthesia, using a 22 g Chiba needle to access a dilated biliary duct in the right and/or left lobe of the liver, under sonographic or fluoroscopic guidance. A 0.35 mm Guide wire was then passed towards the porta hepatis and a tract was dilated with a dilator (8F). A 5F catheter was then passed over the 0.35mm guide wire up to the obstruction site in the biliary duct. Next a 0.35mm hydrophilic guide wire was passed across the stenosis and into the common bile duct (CBD) and duodenum. Stenting or balloon dilation was performed through the hydrophilic guide wire and the tract was embolized with GelFoam (Gelita Medical) or patient's clotted blood, at the end of the procedure, to prevent hemorrhaging and bile leakage.
Balloon dilation of the strictures in right or left hepatic ducts was performed before stenting in 14 (35%) of the patients with balloons (Boston Scientific, Galway, Irland) of 8mm diameters ( Fig.  1-3).
Twenty-six (65%) patients underwent stent placement without predilation. A total of 45 selfexpandable nitinol metallic stents (Cook Medicals, USA) were used in our patients, and 5 patients needed two stents for sufficient bile duct drainage due to obstruction of common bile duct bifurcation and involvement of right and left hepatic ducts. 6-8mm was the diameter of the expanded stents and the length was 8-10 mm.  Among the 50 patients who were candidates for biliary stenting, 15 (30%) had undergone percutaneous transhepatic cholangiogram (PTC) and drainage before stent placement, with the range of 7 to 21 days.
Patient's follow-up took place during the first, second, third, and then the sixth month after insertion of biliary stents. Death was the end point for follow-up in this study.
Stent patency was considered successful in our patients, when there were no lab results or sonographic appearance of biliary tree obstruction.
In the case of recurrent jaundice, CT and/or sonographic examinations were performed to detect restenosis or other complications. The institutional radiological research division of the Tehran University of Medical Sciences has approved this study.
A general physician who was in contact with patients, by phone if necessary, recorded laboratory and clinical examinations.
Patient's survival and stent patency were calculated and descriptive statistics (number and percentage for categorical variables, and number, mean, and standard deviation for continuous variables) were obtained using SPSS 16 software.
Ten (20%) patients failed to treat by stent placement because of unsuccessful technical procedure. The stenosis of biliary tract was completed and passage of guide wire was not possible through the tumor growth. Six patients whose stent insertion failed had proximal biliary ducts obstruction, and four had severe distal stenosis. Six (15 %) patients with successful stent placement died within one month (mean, 22 days) of treatment.
The most important cause of death during this period was primary advanced disease and associated poor conditions (four patients). Other causes were cardio-pulmonary arrest because of sepsis, which was seen in two cases.
Total serum bilirubin resolved to below 1.5 mg/dl in36 (90%) patients with successful stent placement within 30 days. 10% of patients had no significant change in their serum bilirubin level. These patients with unchanged serum bilirubin all died within 40days (16-40days) of stent insertion.
Early complications not leading to death occurred in 28% of cases. Complications included mild free fluid in the abdomen (27%), pain and nausa (45 %), cholangitis (9%), and hemobilia (18%), which were recorded during the first 30 days of post-procedure follow up. None of the above complications needed surgical or interventional treatment.
The median survival time for all patients who underwent stent placement was 3.3 months (95% confidence interval [CI] = 2.27-4.33 months). 15% The most common late procedure-related complication was re-obstruction of the stents in patients who lived more than 90 days, similar to other studies (2) , although it seems inevitable, it can be treated by re-intervention, at least in the majority of the cases. The results of multiple studies confirm that we could reach technical success rates of more than 90%. Most of the complications can be treated conservatively and the mortality rate of the procedure is significantly low (< 2%) in large series of surveys. In our study we had no procedure related mortalities (2) . All of the above could be a good reason for the increased usage of metallic stent placement for palliation of malignant biliary jaundice.
It seems that pre-procedure patient selection should be considered an important factor for biliary stent insertion, especially when poor condition suggests uncertainty for surviving more than a month. Who will be the best and benefit more from supportive care, and who will take more advantage from stent placement as a palliative treatment? We need to study more about the pre-procedure patient's condition as there is a lack of adequate references in this area.